Why can't we have an overnight meal?

Autumn is the season of food. You don't even have to go out. Take a deep breath on the balcony to smell the mellow stew, the fragrance of fried chestnuts and the compatibility of hot pot.

So, you can imagine how angry I was when I heard that someone publicized the dangers of overnight meals.

The harm of online overnight meals

These remarks can be roughly divided into three categories.

The first category is not reliable at all.

Protein in fish and protein in seafood are composed of amino acids. As long as these amino acids are harmless to people, their normal degradation products will not harm people.

Protein, amino acids and other nitrogen-containing substances in fish can be decomposed into nitrogen, trimethylamine, histidine, indole, sulfide, alcohol, organic acids and other products under the growth and metabolism of some microorganisms, which are harmful to human body and called corruption. On the one hand, the shape, color, smell and taste of fish and seafood will change after spoilage, so it is easy to identify them. On the other hand, corruption takes a long time, so there is no need to worry about it regularly. [ 1]

? Is the lo mei itself unsanitary? This statement is very debatable. If stew is unsanitary, don't eat it; If it is sanitary, just pay attention to the storage method and storage time, set the refrigerator temperature reasonably, clean the refrigerator regularly and put it in the refrigerator for one or two nights.

The color of tea darkens overnight because the tea polyphenols contained in it gradually form yellow, red and reddish-brown oxidation products after oxidation. Although the color becomes worse, the clarity decreases and the nutrients are lost in this process, it will not produce substances that are toxic to the human body. [2]

Next, there is some truth, but it is distorted.

Plants need nitrogen for growth. For vegetables, it is mainly nitrate nitrogen. After entering plants in large quantities, it will become nitrate after several physiological processes. [3]

Under normal circumstances, nitrate is harmless to people. However, nitrate can be converted into nitrite by nitrate reductase. After nitrite enters human body, it can not only cause methemoglobin, but also combine with amines in human gastrointestinal tract to generate nitrosamines, which can induce cancer in digestive system, thus causing serious harm to human health.

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According to scholars' research, different treatment methods will have different effects on the same vegetable in the same place. The lower the storage temperature, the more stable the storage environment, the shorter the storage time and the lower the nitrate content. By rinsing, blanching or frying, the nitrate content in vegetables can also be effectively reduced. [4]

In other words, if you want to avoid the intake of nitrite, it is the key to go to a regular business, and you must buy those that meet the pollutant limit in food; Secondly, we can flexibly choose washing, scalding, frying and other processing methods to reduce the nitrite content in food; Finally, low temperature itself can inhibit the activity of enzymes, and it is not long for one night. According to the data consulted, the nitrite content of vegetables and tremella has not changed much after being stored in the refrigerator for one night. [5]

Although the eggshell looks complete and smooth, there are actually many tiny holes, so it is in danger of being polluted. In addition, boiled eggs are more easily absorbed by the human body. Therefore, it is more appropriate to eat it after it is completely cooked than poached eggs. However, it doesn't matter if the eggs are contaminated overnight. If not, why not leave them overnight?

Finally, really pay attention.

Aluminum pots and pans, whether cooking or storing food, may precipitate aluminum. When cooking with aluminum utensils, the release of aluminum is nearly 1 times higher than that of iron pan, and the release of iron is less than 1/3 of that of iron pan. Among them, the refined aluminum pot has flat surface, easy to form oxide film, strong corrosion resistance and wear resistance, and less precipitates; There are many holes in the cast aluminum pot, and the corresponding surface area is large. Because there are many impurities or alloys, the oxide film is poorly formed and the corrosion resistance is weak. [6] Long-term intake of aluminum may lead to dementia.

Therefore, whether cooking or storage, we should try to choose stable materials, such as stainless steel, ceramics, glass, iron and so on.

truth

As long as it is cooked and stored properly, food will not be toxic even if it is left overnight.

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refer to

Xu, Yang. Research progress of spoilage ability of fish spoilage bacteria [J]. Hunan Branch, 20 10/0,2010 (19):130? 133.

[2] Jiang Heyuan. Is overnight tea carcinogenic? There is no scientific basis [J]. Medicine and health, 20 13(2): 59? 59.

Shen Xiuying, Xu Xiaolu. Nitrate accumulation mechanism in vegetables and its influencing factors [J]. Agricultural environment and development, 1998, 15(3): 4? 6.

Zhang, Wang Hao, Li Rui, et al. Effects of pretreatment methods on nitrate and nitrite content in vegetables [J]. China Journal of Food Hygiene, 2008,20 (3): 267? 269.

[5] Like a chicken. Eating tremella overnight can lead to nitrite poisoning? [EB/OL]。 (20 1 1-04- 12)[20 16- 10-24].。 The signed articles published on this website only represent the author's views and have nothing to do with this website. If there is any infringement, you are responsible.

Author: Zhao Yanchang